Brass is any alloy of copper and zinc; the proportions of zinc and copper can be varied to create a range of brasses, each of which has unique properties. In comparison bronze is principally an alloy of copper and tin. Despite this distinction, some types of brasses are called bronzes. Brass is a substitutional alloy. It is used for decoration for its bright gold-like appearance; for applications where low friction is required such as locks, gears, bearings, ammunition, and valves; for plumbing and electrical applications; and extensively in musical instruments such as horns and bells for its acoustic properties.
Brass has a muted yellow color, somewhat similar to gold. It is relatively resistant to tarnishing, and is often used as making casted statues, sculptures, flower vases, figurines, decoration and coins.
some brass items on my window sill.....
Brass has likely been known to humans since prehistoric times, even before zinc itself was discovered. It was produced by melting copper together with calamine, a zinc ore. In the German village of Breinigerberg an ancient Roman settlement was discovered where a calamine ore mine existed. During the melting process, the zinc is extracted from the calamine and mixes with the copper. Pure zinc, on the other hand, has too low a boiling point to have been produced by ancient metalworking techniques. The many references to 'brass' appearing throughout the King James Bible are thought to signify another bronze alloy, or copper, rather than the strict modern definition of 'brass'.
To wax or not to wax is a matter of personal preference. Depending upon the proportions of copper, tin or lead in the alloy, the natural patina of your piece will take on any number of colorations, all the way from black to red to light green. This is known as Edel Patina and is simply natural oxidation - the outermost layer of bronze reacting to oxygen. A thin wax layer protects your bronze however you may prefer allow your bronze to age naturally. If you prefer to halt or slow the ageing process, maintaining a coat of wax to shield your piece from the air's oxidizing effects. In a dry climate, waxing once a year is sufficient; twice a year in areas of high humidity. Outdoors apply two coats, ideally in the heat of the day when the wax is able to more readily be absorbed into the pores of the metal. We recommend premium clear paste wax.
Do NOT use cleaning sprays or furniture polishes containing solvents or other chemicals. They may react to your bronze, discoloring the patina. Older bronzes having their own natural dark patina, or new pieces with a faux antique patina, should NOT be waxed or polished, as this can alter the look and character of the piece.
Edel Patina, a green copper carbonate, protects the bronze naturally, and this layer of oxidation should not be confused with Bronze Disease. Edel Patina normally covers the entire sculpture more or less uniformly and appears as a duller shade of green than Bronze Disease- a condition in which metal produces acid normally hydrochloric or hydro sulfuric acid) internally and begins to disintegrate, while a small fuzzy green or brown patch begging to grow. This disease is mostly caused by exposure to extremes of heat, humidity, acids or environmental pollution. For Bronze Disease there is no quick solution and many method only halt the spread without curing it. The various treatments such as; baking in high temperatures, soaking in distilled water with certain chemicals, and application of chemicals are treatments, but all these methods would change the patina and look of the bronze and may also physically damage the sculpture.
images and ideas conceived by lakshmi arvind
pl.do not copy or steal
Text courtesy: www.xportarts.com